Smolarek, in a 1–1 draw. On 11 September 2005, the following matchday, he suffered in the match against the 1. FC Köln a torn ACL and was out for months. This injury threw him far behind. It wasn't until on 6 May 2006 when Van Der Gun made his return from injury in the last game of the season against Bayern Munich. At the end of the 2005–06 season, he went on to make three appearances in all competitions. However, Van der Gun was released by the club after deciding against renewing his expiring contract. Since leaving Borussia Dortmund, he was called "the unluckiest player to play for the club" by Goal.com, due to injuries. FC Utrecht (first spell) After a season with injury problems at the German side, Van Der Gun returned to the Netherlands for FC Utrecht, signing a three–year contract with the club. He made his debut for FC Utrecht, starting the whole game, in a 2–1 loss against Willem II in the opening game of the season. Since joining the club, Van Der Gun quickly established himself in the first team, becoming FC Utrecht's first choice striker. He scored his first goal for the club, in a 1–0 win against Excelsior on 15 October 2006. This was followed up by scoring his second goal for FC Utrecht, in a 2–0 win against ADO Den Haag. Van Der Gun then scored twice for the club, in a 3–0 win against FC Groningen on 3 December 2006. However, he suffered a torn cruciate ligament in the right knee while warming up prior to a match against NEC Nijmegen on 9 December 2006 and was sidelined for three months. It wasn't until on 9 March 2007 when Van Der Gun made his return from injury, coming on as a 72nd-minute substitute, in a 0–0 draw against Roda JC. However, his return was short–lived when he suffered a knee injury while training and was sidelined for the rest of the 2006–07 season. As a result, Van der Gun was sidelined for six months. At the end of the 2006–07 season, he went on to make eighteen appearances and scoring four times in all competitions. The first half of the 2007–08 season saw Van Der Gun continuing to remain on the sidelines, as he recovered from his knee injury. Van Der Gun made his return from injury, playing for Jong Utrecht